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Congestion Mitigation and Air Quality Improvement (CMAQ) Program

With passage of the Clean Air Act Amendments of 1990, the Congress made great strides in America's efforts to attain the National Ambient Air Quality Standards (NAAQS). The 1990 amendments required further reduction in the amount of allowable vehicle tailpipe emissions, initiated more stringent control measures in areas that still failed to meet the NAAQS-known as nonattainment areas-and provided for a stronger, more rigorous link between transportation and air quality planning. Further establishing this link, one year later, the Congress passed the Intermodal Surface Transportation Efficiency Act-the ISTEA of 1991. This far-reaching legislation brought transportation into the multi-modal arena and also set the stage for an unprecedented focus on environmental programs. Part of this approach was the newly authorized Congestion Mitigation and Air Quality Improvement (CMAQ) Program. The CMAQ program was implemented to support surface transportation projects and other related efforts that contribute air quality improvements and provide congestion relief.

Jointly administered by FHWA and the Federal Transit Administration (FTA), the CMAQ program was reauthorized under the Transportation Equity Act for the 21st Century (TEA-21) in 1998, the Safe, Accountable, Flexible, and Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) in 2005, and most recently, the Moving Ahead for Progress in the 21st Century Act (MAP-21) in July, 2012. Through the close of the SAFETEA-LU period in 2012, the CMAQ program has provided nearly $30 billion in just under 29,000 transportation-environmental projects to State DOTs, metropolitan planning organizations, and other sponsors across the country. As with its predecessor legislation, the MAP-21 provides funding to areas in nonattainment or maintenance for ozone, carbon monoxide, and/or particulate matter. In addition, those State that have no nonattainment or maintenance areas still receive a minimum apportionment of CMAQ funding for either air quality projects or other elements of flexible spending.

The MAP-21 provides just over $2.2 billion in CMAQ funding for each year of the authorization-2013 and 2014. While project eligibility remains basically the same, the legislation places considerable emphasis on diesel engine retrofits and other efforts that underscore the priority on reducing fine particle pollution (PM 2.5). See FHWA's MAP-21 website for additional information.

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Updated: 5/24/2016
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